An absorbent article of this kind is known from SE-C2-502 548. The purpose of the longitudinally extending side-flaps is to impede the lateral flow of urine along the inner casing sheet of the article, and to prevent the wearer's skin coming into contact with excretement. Because the absorbent body is curved by virtue of the contraction of the elastic threads that extend along the edges of the flaps, a collecting volume is formed between the inner casing sheet and the inner surfaces of the flaps.